Fifth wheel



1950 R. A. BRAUNBEQRGIER FIFTH WHEEL 3 Sheets-Sheet 1 Filed Dec. 16,1948 FIG, 2

' INVEN'IOR.

RAYABRAUNBERGER ATTORNEY Nov. 28, 1950 R. A. BRALINBERGER' 2,531,871'

FIFTH m Filed Dec. 16,, 1948 's Sheets-Sheet'2 23 F IG- 7 7 INVENTOR.

RAY. A Baauuaeagm ATTORNEY 1950 4 R. A. BRAUNB'ERGER 2,531,871

FIFIH WHEEL Filed D90. 16, 1948 3 Sheets-Sheet 3 INI'EN'I'OR.

RIWv A. BRMJNBERGER ATTORNEY Patented Nov. 28, 1950 UNITED STATES OFFICEFIFTH WHEEL Ba A. Braunb r r. Chicago. 111- Application December 16,1948, Serial No. 65,577

5 Claims. (01. 289*33-05).

The invention relates to an improvement in fifth wheels which areattached to the top of a tractor and which support the front end of asemi-trailer.

More specifically, the invention relates to a novel construction of afifth wheel that provides for transmitting the load from thesemi-trailer to the tractor in a manner combining rigidity with alimited degree of flexibility.

The base plate of the fifth wheel is rigidly attached to the chassis ofthe tractor. The top plate can rotate about the king pin projecting downfrom the sole plate of the semi-trailer, but otherwise is locked to, andmoves with, the semi-- trailer.

The construction of this fifth wheel transmits the stresses from the topplate to the base plate through novel rockers and a layer of rubber thatpermits absorbing jolts by allowing slight relative motion therebybetween the top and the bottom plate while definitely limiting theextent of this motion.

Both the top plate and the bottom plate are ribbed castings that providebearing surfaces and pivot points with a minimum number of assembledparts, thus precluding loss of rigidity due to wear of bolts or rivets.

The base plate comprises an H- shaped casting each end bar of whichextends along one side bar of the chassis and which is bolted thereto.The cross bar cast integral with the side bars holds the entire baseplate in rigid alignment and pre-. vents the transmission to the chassisof forces tending to distort it.

The top plate, generally circular, has a slot that permits the king pinto find its way to the center of the top plate. The top plate carrieslocking mechanism of any desired type to prevent the king pin leavingits engaged position. One form of locking mechanism is shown in theapplication of Bay A. Braunberger filed November 17, 1948, Serial Number60,575. i

The top plate is supported on' an axis extending crosswise of thetractor and located below the king pin. This permits the top plate totilt front to back while transmitting the load of the front end of thesemi-trailer, the pull to draw it forward, andthe side twist to the baseplate. Ears, extending downward from the top plate, are bored for studslocated in this horizontal axis. Each stud is supported on a novelrocker having a foot embedded in rubber and located in a housing carriedby the base plate. Each rocker can tilt forward, tilt sidewise, or twistslightly.

Thus struc ural inequali e s, wen as jolts, are absorbed.

One obje t o e n n ion is to provide a rubber jolt-absorbing layer,under compression,-

' ensai s the fo in t e $119 Fig, 1 is a plan view of the invention.

Fig. 2 is an end View of the invention.

Fig. 3 is a side'view of the invention.

4 is a plan view of the base plate with the rockers in place.

Fig, 5 is a side view of one of the shoes shown i l 4 with one coverremoved drawn to an nla g d scal Fig 6 is a perspective view of a cover.

Fig} 7 is a section in elevation along lines 1-1 in Fig. 5.

Fig. 8 is an elevation of the shoe with the rockeri place.

Fig. 9 is a section along line S-9 in Fig. 4.

10 is a plan view of a rocker.

The base plate is generally indicated by I. Tihis' plate has side pieces2 that extend longitudinally of the tractor (not shown). These sidepieces are united by an integrally cast bar portion 3 extendingcrosswise. This cross bar is reinforced by ribs Holes 4 provide forconvenient attachment to the chassis of the tractor. To base carries twoshoes generally indicated at 5.

Each shoe comprises an elongated hollow trough-like part 36, narrower atthe ends it than. near the center 3|, and cast integral with the baseplate, and two covers i3, each closing one end of the top of the trough.The sides of the trough are extended upward near its center as indicatedat 9, and horizontal slots l2 are cast into this vertical extension.Each cover it has two vertical surfaces N that align the shorter edge ofthe cover within the sides of the trough and two projecting ears l5 thatare adapted to slide horizontally into slots I2. At the narrow end ofthe plate is a circular hole permitting a single bolt I6 tapped into theshoe to hold the cover down on the trough against movement.

Ribs H rise up from the base under the ends of the trough to transmitthe load.

The space -inside the troughand under the curved covers is concave, freeof sharp edges, generally ellipsoid in shape. Thus the curvature of thebottom longitudinally as shown at I in Fig. 7 is much flatter than thetransverse curvature shown at 8 in Fig. 9.

A rocker generally indicated at H has a web I8 which projects from theshoe and a foot encased in the shoe. This rocker is a casting havingcross web l9, a foot having a bottom surface 28 and a bored hole 2|. Ateach end the foot tapers to a toe 22 as shown in Fig. 10.

The foot is smaller than the space inside the shoe. The entire spaceintervening between shoe and foot is filled by a rubber layer 23vulcanized to the foot.

Studs 24 pass through bores 2| and ears 25 which extend down from thetop plate 29.

When the tractor starts up, the rocker can rock slightly compressing therubber under the toe of the rocker arm and between the .heel of therocker and the cover plate of the shoe.

If there is a sudden jolt in a crosswise plane, one foot can compressthe rubber slightly against the shoe, thus allowing that side of the topplate to descend, while the other foot can compress the rubber againstthe top covers of the other shoe.

I claim:

1. In a fifth wheel, in combination, an elongated cast trough, raisedwall portions on two opposite sides of said trough, horizontal slots insaid raised portions, cover for each end of the trough, one end of eachcover being anchored in said slots, the other end anchored to the troughby a single bolt which prevents the cover sliding along the top of thetrough out of said slots.

2. In a fifth wheel assembly, in combination, a cast-metal base plateadapted to be mounted on the chassis of a vehicle, a pair of oval basinshaving concave internal surfaces free of sharp edges integrally castwith said base plate, sectional concave covers adapted to be fastened tosaid basins, in each basin an elongated shoe of metal of such Shape thatif placed in the center of said basin the distance between it and theinner surface of the basin and the cover will be comparable at allpoints, a curved sole plate on the under side of each of said shoes, avertical rib forming part of each of said shoes and extending up fromthe sole plate through a slot in the covers, a rubber-like substancefilling the space between the shoe and the basin wall, a lower fifthwheel disc supported on the ribs of said two shoes in a mannerpermitting said disc to tilt.

,3. In a fifth wheel assembly of the type in which vertical load andhorizontal traction pull are transmitted to a lower fifth wheel platethat is tiltably supported on the upper ends of shoes mounted in rubberin a. pocket in a base mounted on a vehicle chassis, in combination, acast base plate having two parallel basins integrally cast thereon, theinner surfaces of said basins being ellipsoids with a, common minoraxis; elongated shoes having a curved lower surface generally conformingto the shape of the bottom of the basket in said basins, a vertical ribon each shoe extending above the basin, a resilient rubberlike materialfilling the remaining space inside of the basins, bores in. eachvertical rib having a; common axis said bores being located less thanhalf the length of the shoe above its sole and midway between the endsof the shoe so that the resultant force transmitted through said boresto the shoe will pass through its sole, a lower fifth wheel platesupported tiltably in said bores.

4. In a fifth wheel assembly designed to transmit both vertical loadsand horizontal forces, in combination, an upper fifth wheel discattached to the underside of a trailer, a king-pin extending downwardfrom the center of said disc, a lower fifth wheel disc supporting theupper fifth wheel disc and taking the horizontal forces transmitted bythe king-pin, a horizontal shaft below the lower fifth wheel disc onwhich said disc is tiltably supported, two metal shoes supporting saidshaft each shoe-having a convex sole that is part of an arc whose radiusis several times thatof the distance from the shaft to the bottom of thesole and the length of the shoe being such that the resultant forcetransmitted by the shaft upon the shoe will pass downward at an angle tothe vertical through the sole of the shoe, a support which is curved toconform to the shape of the sole carried by a vehicle, a rubher layerbetween said supports and shoes.

' said rib at a point midway between the ends of the shoe and at adistance above said sole less than a third of the length of the shoe sothat the resultant of the combined vertical and horijzontal forcestransmitted to said shoe passes through the sole of the shoe at alltimes to cause heavier compression of the resilient layer at one endthan the other end without creating tension at the other end of theshoe.

RAY A. BRAUN BERGER.

REFERENCES CITED The following references are of, record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 2,027,990 Lubbers Jan. 14, 19362,289,079 Seyferth July 7, 1942

